76 ANNUAL OF SCIENTIFIC DISCOVERY. 



COATING IRON WITH COPPER. 



A patent has recently been granted in England to a Mr. Tytherleigh, for 

 coating iron with copper, which is represented as successful in overcoming 

 the difficulty hitherto experienced in causing the two metals permanently to 

 unite. 



The principle of the process adopted under this patent is analogous to that 

 of soldering, the difference being that the granulated metal used in soldering 

 is spread over the surface of the iron, instead of being merely applied to the 

 edges which the workmen desires to unite. Supposing, for example, that 

 it is intended to coat a sheet of iron with brass, the patentee prepares the iron 

 by what is technically called "pickling," or cleansing it. He then spreads 

 evenly over the surface the common brass solder, and over this he spreads a 

 quantity of borax to act as a flux. The sheet so prepared is placed in a fur- 

 nace heated to the proper degree, and after remaining in the fire for about 

 ten seconds, is withdrawn and permitted to cool, the short space of time 

 mentioned being amply sufficient to ensure the union of the metals. Iron 

 thus coated has been subjected to the severest tests in annealing, rolling and 

 planishing, and has successfully endured them all, the brass being so firmly 

 united to the iron that nothing short of actually filing it down is able to 

 effect a separation. By using a funiace with doors on opposite sides, and 

 by the adoption of proper machinery, sheets of any size may be thus coated, 

 and the process may be successfully performed on both sides of the sheet at 

 the same time. For coating iron nails with brass and copper, the process 

 employed is as follows : The metal is fused in a crucible or other proper 

 vessel, and the flux being added, the articles to be coated are placed in the 

 vessel. This method, which is applicable to the coating of nails and other 

 small articles, affords results equally successful with sheets of flat surfaces. 



The advantages of such an invention are obvious. The innumerable 

 articles now made of brass or copper may in future, should this invention be 

 extensively adopted, be made of iron covered with either of those metals. 

 Strength, lightness, and cheapness are amongst the principal advantages de- 

 rivable from the use of the new material ; and in addition, the danger arising 

 from oxidation in the case of iron may be entirely obviated. 



COATING ARTICLES OF IRON WITH METALLIC ALLOYS. 

 I 



An American patent has recently been granted for the above purpose to 



Joseph Poleux, which consists in preparing iron to receive the coating, by 

 immersing it in concentrated mineral acids. As soon as the articles to be 

 cleansed are immersed in the acid, one, two, or more small pieces of spelter 

 are dropped among them, or the spelter is passed into the acid with the 

 articles. The acid acts at once and rapidly on the spelter, holds in solution 

 what it dissolves, and precipitates a film of it on the minutest portions of 

 the iron surfaces the instant the acid has cleansed them, and this film pro- 

 tects such portions from any finther action of the acid while remaining in 

 it. Without the spelter, undiluted acid could not be used without great 

 waste and injury to small or thin articles placed in it. The articles are next 



